DESCRIPTION OF THE RELATED ART When a watercraft moves at a higher speed, the waterdrag exerted on the hull of the watercraft is bigger and the amount of fuel consumed greater. Many solutions have been proposed to increase the speed and reduce the fuel consumption of these watercraft by reducing the waterdrag, but all of these solutions have drawbacks to overcome.

One solution is mentioned in W091/11359 entitled HIGH STABILITY DISPLACEMENT HULL DEVICE which consists mainly of two slender struts, shaped like water skis, fixed to the hull of the craft, so that only these two struts will come into contact with water when the craft moves, thus reducing the surface of contact and friction between the hull and water. However, the water drag is still great as the great mass of the whole craft has been transferred to the two struts.

Another solution is mentioned in US Patent 576146 entitled SURFACE EFFECT PLANING PONTOON SEAPLANE to be adapted to very large ships, which consists of a hollow rectangular bottom with two sidewalls and two wavelike slopes at the bow and stern of the craft bottom. This hollow bottom forms an air cushion between the hull and the water surface, thus will reduce the contact surface between the two and the friction exerted on the hull by water when the craft moves.

However, this waterdrag reduction only happens when the craft moves at normal speeds; at greater speeds, water will push the air cushion out of the hollow bottom and the bottom of the craft will come back into contact with water, resulting in increased drag of water on the hull.

Another structure is proposed by US Patent 6439148 entitled LOW DRAG HIGH SPEED SHIP where the moving craft is lifted by ski-like pontoons whose bottoms are covered with gas-filled cavities serving as air cushion to reduce the _drag of wa er on the, ails. 4Although this solution is effective in reducing water drag, it will be difficult to insure a sufficient air cushion when the craft is moving at greater speeds.

Recent solutions have tried to propose different watercraft designs using a moving surface in contact with water to reduce water drag. However, these solutions still have many limitations to be overcome.

An example is the structure mentioned in US Patent 6,0508, 188 entitled DRAG FREE HULL FOR MARINE VESSELS which proposed for moving surface in contact with water the outer surface of an endless revolving tubular belt of which the inner surface defines a fluid-tight chamber which can be inflated with a compressed gas. This is a complicated structure which consumes much energy for the rotation of the endless belt as well as for the friction between the sealing part at both ends of the endless belt and the belt itself. The author of the invention claims that his solution will eliminate the water drag completely when the rotation of the belt has the same speed as the ship/boat, that is when the comparative speed of the outer surface of the circular belt and the body of water in contact is equal to zero.

But as a matter of fact, when this comparative speed is null, the structure will not lift up the watercraft and the hull will be in contact with water.

Waterdrag between the contact surface and water is necessary for the watercraft to be lifted, except for light boats with the contacted with movable surface are buoy. That is why it is impossible to eliminate waterdrag completely if the hull needs to be lifted up, especially when the watercraft is a heavy ship.

Another solution is proposed by the Russian Patent RUZ105693 entitled HIGH SPEED BOAT, where two sets of disks are fixed along the sides of the watercraft with an upward slant to the longitudinal axis of the hull and a rotor at the bow that will produce propulsion and lift up the front of the craft and also create an air cavity stream under the hull. The disks at the sides of the hull will have one surface in contact with air and the other surface in contact with water; and as the disks rotate, the drag friction will be reduced. However, this solution has the following drawbacks : - Since the surfaces of the disks are aligned with the longitudinal axis of the vessel and also parallel with the surface of water, as illustrated in Figure 3 of the invention, the air cavity stream produced by the rotor when the vessel moves at medium speed will not be large enough for the disks to be solely in contact with water on one surface and friction with water will not be reduced.

- The rotor at the front of the ship will use a lot of energy to create the needed air cavity stream. In the process, it will also produce waves which break against the hull, encumber the progress of the vessel and cause more friction.

- The air cavity stream created by the rotor varies with the speeds of the vessel, whereas the disks only produce the expected result when this cavity stream is large enough. That is why this system demands a high and regular speed.

- The system seems to work only with small-sized vessels. It will be difficult to create an air cavity large and long enough for large vessels. Using several rotors and sets of disks will cause problems as the cavity stream will overlap one another.

- As the disks are fixed with an upward slant so as to increase the lift of the hull and only the lower surfaces of the disks are in contact with water, the movement of the vessel is impeded by the waves on the water surface.

SUMMARY OF THE INVENTION: The present invention proposes a principle for reducing the drag on bodies or transportation means moving at high speed in water or air and applies this principle in the creation of a drag-reducing structure applicable to bodies or transportation means traveling in water or air which will enable such bodies or transportation means to move in the respective environment with little effect from hydrodynamics or aerodynamics.

The principle for reducing drag from the fluid or gaseous environment for bodies moving in such an environment is as follows : When a body is moving in an environment, the drag exerted by this environment on the body will be reduced or eliminated if the surfaces of the body in contact with that environment are also moving in the same direction as the body with about the same velocity as the body. In other words, when. a body is moving in its environment, the surfaces of the body in contact with the environment must be able to move and this movement has the same axis of motion as the body in motion and progresses in the opposite direction of motion of the progress of the body, and the velocity of the surfaces when compared with the environment must be very small or nearly equal to null.

For example, when a car is moving on a road, the surface of the road is the environment, the points of contact of the tires with the road always have a velocity equal to zero when compared to the surface of the road, and a velocity equal to the speed of the car when compared to the axle of the tire; that is the points of contact. between the tires and the road are stationary as the surface of the road never moves even if the car is moving.

For objects or means of transportation like planes or rockets, when they are moving in the atmosphere at high speeds, the air around these bodies becomes dense as a fluid; the application of the above principle by replacing the surfaces in contact with the atmosphere by moving surfaces will bring about favorable improvements in the motion of these objects in the atmosphere.

In the same way, drag reduction for means of transportation on the surface of water is subject to the following requirements : - first, all surfaces in contact with the surrounding environment (water) must be able to move with about the same velocity as the means of transportation, in the same or about the same line of motion of the means of transportation and in the opposite direction of motion with the means of transportation. In other words, these means of transportation need a new structure where the unmoving surfaces in contact with water of the existing vessels will be replaced by moving surfaces.

- second, the above-mentioned structure needs to have extra lifting force so that only the moving surfaces will be in contact with water instead of the hull of the vessel, and for the vessel to be lifted up, the contact surfaces must produce friction (even small) and create a downward current bringing about a lifting force.

Naturally, this point does not comprise cases where the contact surfaces are intrinsically buoyant, such as hollow volumes or floats, as will be mentioned later in this document. Different ways to increase the lifting force are: increase the degree of slant of the contact surfaces width the surface of water; reduce or increase the speed of movement of these surfaces so as to create differences of velocities between these surfaces and the surrounding water and the resulting friction will create a downward current leading to the lifting force.

In case the comparative velocity between the surfaces of contact and the surrounding water is null, no lifting current will appear. The necessity of a lifting force will not allow the total elimination of water drag as explained in the US Patent 6,0508, 188 DRAG FREE HULL FOR MARINE VESSELS.

Third, for the means of travel to bear little influence from waves, the moving surfaces in contact with water must be lying deep in water.

PRINCIPAL NATURE OF WATERDRAG-REDUCING STRUCTURE FOR WATER-SURFACE MEANS OF TRAVEL The different types of means of transportation in use today like ships, boats, canoes, barges, sports speedboats, water-skis, water planes, jet skis, pedalos, powerboats, hydrofoils, etc. , all have their hulls or other fixed surfaces in contact with water. These fixed surfaces bear great water drag when the vessels move at high speed, resulting in limited speeds, fuel consumption and waves that could cause harmful effects to the surrounding environment. The present invention proposes structures to be fixed to existing watercraft or to be designed together with future watercraft so as to enable these craft to reduce water drag exerted on them, move at higher speed, consume less fuel and create fewer waves.

The main parts of the waterdrag-reducing structure for watercraft are: - endlessly-moving surfaces replacing the fixed surfaces in contact with water of existing watercraft when they move on the surface of water ; - these contact surfaces will be fixed with an upward slant so as to exert a lifting force for the watercraft; - the angle of the slant may be varied and the speed of motion of these surfaces may be changed so as to enable the watercraft to move on the surface of water at different speeds; - these moving surfaces will remain entirely under water to keep the watercraft from the action of waves.

The structure proposed for the reduction of waterdrag on watercraft consists of the following main components: - endlessly-moving surfaces created by a portion of the rim of endlessly- rotating disks in contact with water of (or similarly, endlessly-moving surfaces created by flat panels fixed to the rim of endless chains or endless belts, the flat panels and the surfaces of chains or belts being parallel or nearly parallel to one another); as theses surfaces in contact with water move, the comparative velocity between these surfaces and the surrounding water is small, friction with water is reduced.

When the watercraft is moving, the endless disks or chains or belts will be positioned as followed: -. the surfaces of the disks/chains/belts in contact with water will make an upward slant with the fore-and-aft axis of the watercraft, therefore a current will form around these contact surfaces and move backward and downward creating a lifting force (the velocity between the contact surfaces and the surrounding water still exists, even small).

NB: the angle of the upward slant mentioned in this invention is the angle of the intersection of the surface of the disk and the vertical surface containing the longitudinal axis of the watercraft. This angle will be hereinafter referred to as the alpha angle.

- The surfaces of the disks will form an angle with the surface of water or an angle with the transversal axis of the watercraft ; consequently, only the lower surfaces of the disks will be in contact with water and these surfaces will be moving endlessly with an axis of motion nearly parallel to the axis of motion of the watercraft and moving in the opposite direction of the watercraft.

NB : The angle of the surfaces of the disks compared to the transversal axis of the watercraft mentioned in this invention is the angle of the intersection of the surfaces of the disks and the vertical surface containing the transversal axis of the watercraft, hereinafter referred to as the beta angle.

In order to ensure the above features of the drag-reducing structure and to add other capacities such as starting the motion, braking, steering, accelerating, etc. , additional components of the structure are: - the endlessly-moving surfaces of the disks may take different alpha and beta angles; - the rotation of the endless disks/chains/belts may be given different speeds.

For this same purpose, the present invention also proposes various details, components, positions for these details in order to ensure the maneuverability of the watercraft, ameliorate the efficiency of the propeller, reduce the bulk of the whole construction and impart better reduction of friction on the watercraft.

At the same time, the present invention also proposes a drag-eliminating structure for light watercraft: this structure will comprise chains or belts on which endless floats or hollow volumes are fixed and the latter floats or hollow volumes will give complete buoyancy to the watercraft and there is no need to create the lifting force. This structure consists of the following: Endless chains or belts of which the surfaces will carry thick floats or hollow volumes forming the contact surfaces with water. Such chains or belts are fixed on the watercraft like the chains of a tank. But whereas the chains of a tank moving in water only propel the tank forward, the endless chains or belts fixed on the watercraft will work as contact surfaces with water and will give the watercraft both buoyancy and propulsion. For better results, there should be two pairs of such chains or belts: one at the front and one at the rear of the watercraft, both fixed with- an upward slant. The floats or hollow volumes on the chains/belts will ensure the buoyancy of the craft. The weight of the watercraft is spread evenly all over the floats or hollow volumes. When the watercraft is moving, the upward slant of the chains or belts will create a lifting force. Such a structure will enable light means of transportation on water, including the ones using human muscular force, to reduce waterdrag even when they move at medium or slow speeds.

To attain the above objectives to reduce waterdrag for the watercraft, the present invention proposes the following plan for the waterdrag-reducing structure for watercraft with the following components : - at least two rows of disks with at least two disks on each row; these rows of disks are fixed symmetrically on two sides under the hull of the vessel (compared to the lengthwise axis of the vessel); - the surfaces of these disks are at an upward angle with the longitudinal axis of the watercraft, which angle should not exceed 30 degrees so as to increase the contact surface with water; - the surfaces of these disks are also at an angle with the transversal axis of the vessel, which angle should be less than 30 degrees so as to increase the contact surface with water - these disks can rotate endlessly thanks to a bearing set between the center of the disk and the central axle of the disk or between the central axle of the disk and the frame holding the central axle of the disk or between the central axle of the disk and the hull of the watercraft ; - thanks to the symmetrical arrangement of the disks on the two sides under the hull of the vessel, the weight of the vessel is distributed equally on the disks.

When the watercraft moves on the surface of water, the upward slant and the lateral slant of the disks will stay unchanged. When the watercraft moves forward, the upward slant will lift up the disks and the watercraft. And when the watercraft moves forward on the surface of water, only the lower portions of the disks will be in contact with water, and as the disks rotates, the parts of the disks in contact with water moves almost parallelly with the axis of motion of the vessel and opposite to the direction of motion of the watercraft. The comparative velocity of the portion under water of the disks and the water surrounding them is very small; consequently, the water drag is greatly reduced. At the same time, as the parts of the disks in contact with water are under water, the watercraft moving on the surface of water stands less action from waves.

- In this preferred embodiment, at least two disks or two rows of disks are symmetrically fixed on the hull of the watercraft so that they form an upward slant with the longitudinal axis of the vessel and a lateral slant with the transversal axis of the vessel and it is possible to change these slants; these disks can rotate endlessly thanks to the bearings as described previously; the disks with the upward and lateral slants which can be changed to be wider or smaller so that the lifting forces will be stronger or weaker will enable the watercraft to move faster or slower with the hull of the vessel all the time out of the water. The changes of the slants also enable to increase or decrease the portions in contact with water of the surfaces of the disks as proper to the speed of the vessel.

- For this purpose, it is better to have a hinge between the disks and the central axles of the disks, or between the central axles of the disks and the hull of the watercraft, or between the central axles of the disks and the frame holding these central axles ; at least two bars are fixed on the upper surface of each disk or on the central axle of each disk, one bar on the longitudinal axis of the disk and the other bar on the transversal axis of the disk. The two bars will work as adjusting shafts allowing the adjustment of the upward slant and lateral slant of the disk.

- Also for this purpose, it is better for the disks to be fixed to a central axle which is in turn fixed to an adjusting shaft controlling the adjustment of the disks.

The central axle and the adjusting shaft will form a fixed angle which should be less than 30 degrees; the adjusting shaft will be fixed to the hull of the watercraft vertically (that is, at a right angle with the floor of the watercraft); thus, the fixed angle of the central axle of the disk and the adjusting shaft will be the angle formed by the surface of the disk and the surface of water; when the watercraft begins to move, the disks will be positioned so that the upward slant has a wider angle to give a greater lifting force; when the watercraft increases its speed, turning the vertical adjusting shaft in an arc will rotate the disks and the upward slant of the disks will gradually become the lateral slant, and when the speed of the watercraft becomes greater, the axis of the surface of the disks gradually becomes more parallel with the direction of movement of the watercraft ; consequently, the qsks rotate more easily and the waterdrag, becomes smaller.

- In this respect, it is better for the waterdrag-reducing structure to have also the ability to work as a brake; this is possible when the vertical adjusting shaft rotates and the disks will make an arc and be positioned so that the surface of the disks and the surface of water make a downward angle to the direction of movement of the watercraft ; in such a position where the surfaces of the disks make a downward angle and right angle with the axis of movement of the watercraft, the portion in contact with water will put up resistance to water and reduce the speed of the watercraft.

- In this preferred embodiment, it is better to have twodisks or rows of disks with each disk fixed to its vertical central axle; the vertical central axles of the disks will be fixed to the hull of the watercraft or to the frames holding these axles, which frames will then be fixed to the hull of the watercraft ; the disks will be fixed on the watercraft in such a way that the longitudinal axis of the surface of the disk forms an upward angle with the axis of the propeller of the vessel (the screw propeller or the water expelling pipe), or with the axis of the hauling apparatus; and the transversal axis of the surface of the disk forms a lateral angle with the transversal axis of the watercraft ; thanks to the upward slant with the longitudinal axis of the propeller, the disks will be lifted up when the propeller or the hauling apparatus works and moves the watercraft forward ; and thanks to the lateral angle with the transversal axis of the watercraft, the underwater portions of the disks will move parallelly with the axis of movement of the watercraft and in the opposite direction of the direction of movement of the watercraft, resulting in a small comparative velocity between the underwater portions of the disks and the body of water through which they move; consequently, water drag is greatly reduced; and at the same time, as the portions in contact with water of the surfaces of the disks remain under water, the action of the waves on the watercraft is also reduced.

In this preferred embodiment, two disks or two rows of disks with each disk fixed to its vertical central axle which is fixed to the hull of the watercraft or to a frame holding the vertical central axles, which frame is then fixed to the body of the surface-moving watercraft ; the disks will be fixed to the hull of the watercraft with their surfaces parallel to the longitudinal axis of the watercraft or with a small upward slant ; the surfaces of the disks will also have a lateral slant with the transversal axis of the watercraft; the weight of the vessel will be arranged in such a way that the stern will be heavier than the bow, thus, the longitudinal axis of the vessel will make an upward slant with the surface of water, leading to a greater upward slant with the surface of water; that is why, when the propeller or the hauling structure works and moves the watercraft forward, the disks are lifted up; the surfaces of the disks form a lateral angle with the transversal axis of the watercraft (and also with the surface of water); the lower portions of the disks which remain under water can move with an axis parallel to the axis of movement of the watercraft in the opposite direction of the direction of movement of the watercraft; that is why, the comparative velocity between the underwater portions of the disks and the body of water surrounding them is small and the friction caused by water is greatly reduced; and as the lower parts of the disks in contact with water remain under water, the watercraft does not bear too much action from waves at the surface of water.

- In this preferred embodiment, it is better for the water-reducing structure to have also the braking or lifting capability; this is possible when at least one pair of disks of the two symmetrical rows of disks are equipped with an apparatus that allows reducing or stopping the movement of the watercraft; the reduction of speed or stoppage of movement is caused when the apparatus brings about an increase in the friction between the surfaces of the disks and the body of water they are in contact with, leading to the reduction of speed of the watercraft ; this is also possible when in each symmetrical pair of rows of disks, at least one pair of disks symmetrically positioned on the hull of the watercraft can be operated to impose the reduction or complete stoppage of the speed of the watercraft as the watercraft starts moving or is moving at low speed; this imposed reduction or complete stoppage of movement of the watercraft will cause the friction between the surfaces of the disks and the surrounding water to increase the lifting force so that the watercraft can start moving or move at a low speed.

- In this preferred embodiment, it is better that the drag-reducing structure to have also a steering capability; this is possible when one disk of each pair of disks can be operated to impose the reduction or complete stoppage or increase of the speed of the watercraft ; this imposed reduction or complete stoppage or increase of speed of the watercraft will cause a difference between the frictions supported by- the two rows of disks; as a result, the watercraft will change its course to the direction imposed.

- In this preferred embodiment, it is better that at least one pair of disks of each pair of rows of disks symmetrically positioned on the hull of the watercraft can be operated to rotate by driving force from a motor ; the velocity of the sides of the disks should be greater than the velocity of the hull of the watercraft compared to the surface of water; the lower portions of the surfaces of these disks which are forced to rotate by driving force remain under water and move in the opposite direction to the direction of movement of the watercraft, creating a current moving downward and backward, resulting in more thrust and lift for the watercraft.

- for this purpose, it is better that there are ribs, waves, paddles, holes on the surfaces of the disks which are forced to rotate, or these disks have the shape of a wind vane ; thanks to these shapes, when the disks are forced by driving force from a motor to rotate, a stronger current'will be formed and as this current moves backward and downward, more thrust and lift will be given too the watercraft ; as a result, the watercraft will be able to travel at different speeds with its hull always out of water.

- In this preferred embodiment, it is better for the rows of disks to consist of overlapping disks with the fish scale pattern or the roof tile pattern; this arrangement will enable the comparative movement between the lower portions of the disks and the surrounding water to be more direct, the currents formed not being deflected by the rotation of the overlapping-disks ; consequently, the drag-reducing structure will consume less energy and will also become less bulky.

- In this preferred embodiment, two pairs of disks or two rows of pairs of disks are symmetrically fixed on the hull of the vessel on both sides of the longitudinal axis of the vessel, with one pair fixed under the kull at the bow and the other pair fixed under the hull at the stern ; the pair of disks or rows of pairs of disks at the stern will have an upward slant that can be adjusted and turned into a downward slant (compared to the longitudinal axis of the vessel); thanks to the adjustability of the disks/rows of disks at the stern, the upward <BR> <BR> slant can be turned into a downward slant; that is why, when the watercraft move<BR> <BR> . on the surface of water, its longitudinal axis will have an upward angle with the surface of water; consequently, the surfaces of the disks will give a different upward angle; as a result, the watercraft can move at different speeds with its hull always out of water, - In this preferred embodiment, at least one pair of disks or one pair of rows of disks are fixed symmetrically under the hull of the watercraft, and the two disks of the pair or the two rows of disks of the pair of rows of disks form a V, the surfaces of the disks having symmetrical lateral angles and the lower parts of the disks of the pair being near each other ; the lower parts of the symmetrical disks pointing to each other will force the current of water to move in the space between them, reducing the centrifugal movement of the body of water surrounding the lower parts of the disks and directing it to the back in a straight line, thus, reducing the consumption of energy.

- For this purpose, it is better for the propelling apparatus of the vessel such as the screw-propeller or the water jet pump to be positioned in the middle of the V-shaped arrangement of the two disks or pairs of disks; when the propulsion apparatus like the screw propeller pushes a current of water backward, a large amount of water which used to be diverted by the centrifugal force created by the rotation of the propeller now is straightened, thus, creating more thrust for the watercraft.

- In this preferred embodiment, it is better for the waterdrag-reducing structure to have also a steering capability for the watercraft ; this is possible by fixing to this structure at least one component which will monitor the steering of the watercraft by acting like a rudder, this steering component consists of a vertical endless disk with its central axle fixed to a frame holding this central axle, which frame fixed to a vertical shaft monitoring the rotation of the axle; the longitudinal axis of the vertical surface of the disk is parallel to the longitudinal axis of the watercraft; the lower portion-of the, dmk is under water when the watercraft moves on the surface of the water; being the only part under water, this lower portion of the disk will rotate when the watercraft moves on the surface of water and thus, will not create any waterdrag although acting as a rudder; the rotation of the vertical axle of this disk will deflect the current backward <BR> <BR> <BR> <BR> opposite to the direction of movement of the watercraft, allowing it to change its<BR> <BR> <BR> 9_--pk4l-ge its course with little waterdrag on account of the low comparative speed between the contact surface of the disk and the body of surrounding water.

- In this preferred embodiment, the disks may be hollow or porous with thick walls or with supporting frames or the disks may be shapes like cylinders or truncated cones or like two reverse truncated cones one on top of the other or like top sections of spheres or like two reversed sections of spheres one on top of the other or like conic sections ; thanks to the thick walls of the hollow disks and thanks to the above shapes, the disks will obtain more sturdiness and more buoyancy.

- For this purpose, it is better for the disks to be made of resilient substances and shaped like automobile tires and filled with air and mounted on rims like wheels; the disks will gain in buoyancy and can work as shock absorbers for the watercraft.

- In this preferred embodiment, the waterdrag-reducing structure will give the watercraft the capability to travel on land. This is possible when the disks made of resilient materials work as wheels permitting the watercraft to move on land. At least four disks fixed on both sides of the hull of the vessel have maneuverable central axles parallel to the transversal axis of the watercraft ; thanks to these disks which have become wheels, the watercraft move on land like a land vehicle.

- In this preferred embodiment, the lower part of the hull of the watercraft will have V-shaped or W-shaped cavities crosswise and the rows of disks are arranged along the walls under the hull of the watercraft ; as the disks are arranged close to the walls under the hull of the watercraft, the distance separating the disks from the hull of the vessel is small, thus, giving better balance to the vessel when it is moving.

In another respect, the present invention proposes a waterdrag-reducing structure for watercraft where the endless disks are substituted by endless chains consisting of : at least one chain stretched at both ends by two pinion wheels with their axles fixed to a frame, panels are fixed to the rings of the chain on the outer face and the surface of the panels are parallel to the surface of the chain ; this chain is fixed to the hull of the vessel through the axles of the pinion wheels or through the frame; the chain will be fixed to the hull so that the surface of the chain, which is also the surface of the panels, forms an upward slant with the longitudinal axis of the watercraft and a lateral slant with the transversal axis of the watercraft; since the surfaces of the panels on the chain form an upward slant with the hull of the watercraft, when the watercraft moves thanks to the thrust from the propulsion apparatus or the pull from the hauling apparatus, the panels are lifted up; and since the surfaces of the panels form a lateral slant with the transversal axis of the hull of the watercraft, only the lower portion of the chain stays under water when the watercraft moves ; and since these panels on the lower face of the chain remain under water and can move with an axis of motion parallel to the axis of motion of the watercraft and in the opposite direction of the movement of the watercraft, the comparative velocity between the surfaces of the panels on the lower face of the chain under water and the surrounding body of water is small, resulting in noticeable reduction of water drag; and since the surfaces of the panels on the lower face of the chain in contact with water are under water, the watercraft which travel above the surface of water does not bear much action from the waves.

- In another respect, the present also proposes a waterdrag-reducing structure for watercraft, where the endless disks are substituted by endless belts; these endless belts consist of : flat panels of rectangular or circular shape, on whose surfaces and perpendicularly to these surfaces are fixed axles with bearings, two boards either elliptic or like rectangles with two circular ends, on whose rims or near the rims of one of their faces are grooves or furrows running all round their perimeter; these two panels are placed parallel with their grooved or furrowed surfaces facing each other; the flat panels are placed between the two boards so that their axles with bearings will run in the. grooves or furrows of the boards ;,,,.- the flat panels are fastened together by such means as springs or rubber cord through their axles, forming a endless belt with the flat panels pointing out of the circumference of the two boards; the surfaces of the flat panels are parallel to the surfaces of the two boards; in this way, the flat panels are joined together and formed an endless belt <BR> <BR> <BR> with bearings running on the rim of the circumference of the two boards ;<BR> <BR> on the surfaces of the boards are the shafts joining the boards to the hull of the watercraft ; the surface of the belt (formed by the perimeter of the belt) which is also the surface of the flat panels has an upward slant with the longitudinal axis of the watercraft ; the surface of the belt has a lateral slant with the transversal axis of the watercraft ; the upward slant of the flat panels of the belt with the longitudinal axis of the watercraft will lift up the panels when the watercraft moves ahead thanks to the thrust from the propulsion apparatus or the pull from the hauling apparatus ; the lateral slant of the flat panels of the belt with the transversal axis of the watercraft will keep only the lower part of the surface of the belt under water when the watercraft moves on the surface of water; since the panels on the lower part of the belt are under water and moves with an axis parallel to the axis of motion of the watercraft and in the opposite direction to the direction of motion of the watercraft, the comparative velocity between these underwater surfaces of the panels and the surrounding body of water is small, resulting in the reduction of waterdrag; at the same time, since the contact with water of the panels takes place under water, the watercraft is free of much action of the surface waves.

- In another respect, the present invention proposes a waterdrag-reducing for watercraft consisting of at least an endless tubular belt shaped like a motorcycle inner tube, made of soft or elastic material; the belt is stretched out by at least two large pulleys fixed on a frame ; the grooves of the pulleys are the same width as the belt; therefore, the belt running on the large pulleys will form an endless belt ; this endless belt is fixed to the hull of the watercraft through the axles of the pulleys or through the frame holding the pulley; the longitudinal axis of the belt forms an upward slant with the transversal axis of the propulsion or the hauling apparatus of the watercraft ; the vertical axis of the surface made by the circumference of the belt makes a right angle with the horizontal axis of the watercraft ; the hollow or porous structure of the belt and the width of the belt increase the buoyancy of the watercraft ; the upward slant of the belt with the transversal axis of the propulsion or hauling apparatus helps keep the lower face of the belt in contact with water and this contact surface moves in the opposite direction of the direction of motion of the watercraft, pushing the current of water downward and backward and lifting the belt up; when the watercraft moves ahead with enough speed, only the lower part of the belt is in contact with water and as this lower part moves to the opposite direction of the direction of the watercraft, friction with water is reduced.

- In another respect, it is better for the waterdrag-reducing structure to consist of at least two belts, one fixed under the front part of the watercraft, the other fixed under the back part of the watercraft ; the belts are made of soft or elastic material and has the shape of an inner tube for motorcycle wheels; the belts are stretched out by at least two large pulleys fixed to a frame; the grooves of the pulleys are the same width as the belts and the belts running on the pulleys form endless belts; these endless belts are fastened to the hull of the watercraft through the axles of the pulleys or through the frame holding the pulleys; the longitudinal axis of the surface of the belt makes an upward angle with the transversal axis of the watercraft ; the vertical axis of the surface of the belts makes a right angle with the horizontal axis of the watercraft ; the hollow or porous structure of the belt and the width of the belt increase the buoyancy of the watercraft; the upward slant of the belt with the transversal axis of the watercraft has been maintained; the weight of the watercraft is evenly distributed to all the surfaces of these belts; when the vessel moves, only the lower faces of the belts are in contact with water and moves in the opposite direction of motion of the watercraft; as a result, the current of water is deviated downward and backward and the belts are lifted up; when the watercraft moves forward fast enough, only the lower part of the belt is in contact with water and as this lower part moves to the opposite direction of the direction of the watercraft, friction with water is reduced.

- In another respect, the present invention proposes a waterdrag-reducing structure for watercraft consisting of at least one endless belt or chain, which belt is stretched out by at least two large pulleys with central axles fixed to a frame, or which chain is stretched out by at least two chain gears with central axles fixed to a frame, on the outer surface of the belt or chain are fixed hollow volumes or floats shaped like cylinders or square columns or rectangular columns; these hollow volumes or floats are parallel to one another and perpendicular to the longitudinal axis of the endless belt or chain; this endless belt or chain is fastened to the hull of the watercraft through the frame holding the pulleys or gears; the lower surface of the belt or chain makes an upward angle with the transversal axis of the propulsion apparatus or hauling apparatus of the watercraft ; the vertical axis of the surface of the belt or chain makes a right angle with the horizontal axis of the watercraft ; the hollow or porous character of the volumes or floats fastened to the belt or chain and their large volume increase the buoyancy of the watercraft ; on account of the upward angle of the lower surface of the belt or chain with the transversal axis of the propulsion or hauling apparatus, when this apparatus enters in operation, the volumes or floats on the lower part of the belt or chain enter in contact with water and move in the opposite direction of the direction of motion of the watercraft, deviating the current of water downward and backward and consequently are lifted up; when the vessel moves forward with enough speed, these volumes or floats are in contact with water and moves in the opposite direction of the direction of the vessel, leading to the reduction of waterdrag.

- In another respect, it is better if the waterdrag-reducing structure for watercraft consists of at least two endless belts or chains, one belt or chain fixed under the front part of the hull of the watercraft, the other fixed to the back part of the hull of the watercraft ; the belts are stretched out by at least two large pulleys or the chains are stretched out by at least two chain gears; the pulleys or chain gears have central axles fixed to a frame which hold the pulleys or chain gears; on the outer surface of the endless belt or chain are fixed hollow volumes or floats shaped like cylinders or square columns or rectangular columns ; these, hollow volumes or floats are parallel to one another and perpendicular to the longitudinal axis of the endless belt or chain; this endless belt or chain is fastened to the hull of the watercraft through the frame holding the pulleys or gears ; the lower surface of the belt or chain makes an upward angle with the transversal axis of the propulsion apparatus or hauling <BR> <BR> . apparatus of the watercraft ; the vertical axis of the surface of the belt or chain makes a right angle with the horizontal axis of the watercraft; . the hollow or porous nature of the volumes or floats fastened to the belt or chain and the large size of these hollow volumes or floats increase the buoyancy of the watercraft; on account of the upward angle of the lower surface of the belt or chain with the transversal axis of the watercraft which is maintained when the watercraft moves ahead; the weight of the watercraft is evenly distributed among the belts or chains, therefore increasing the lifting force; and when the watercraft moves ahead, the volumes or floats on the lower part of the belt or chain enter in contact with water and move in the opposite direction of the direction of motion of the watercraft, deviating. the current of water downward and backward and consequently are lifted up ; when the vessel moves forward with enough. speed, these volumes or floats are in contact with water and moves in the opposite direction of the direction of the vessel, leading to the reduction of waterdrag.

BRIEF DESCRIPTION OF THE DRAWINGS : The present invention will be described in detail using the attached drawings.

FIG. 1 is a cross-sectional schematic presentation of a watercraft with a waterdrag-reducing structure; the watercraft is in motion on surface of water; an extra waterdrag-reducing structure functioning as a rudder is at the stern ; FIG. 1A is a cross-sectional schematic presentation of a watercraft with a waterdrag-reducing structure; the watercraft is in motion on surface of water; the disks in this structure are arranged in the manner of tiles; FIG. 1B is a top view through the body'of the vessel of the waterdrag- reducing structure in FIG. 1A. The lines on the disks mark the intersections of the surfaces of the disks and the surface of water, representing the angle formed by the surface of the disks and the surface of water ; FIG. 1C is a cross-sectional schematic presentation of a watercraft with a waterdrag-reducing structure ; the watercraft is in motion on surface of water ; the disks in this structure are arranged in the manner of fish scales; FIG. 1D is a top view through the body of the vessel of the waterdrag- reducing structure in FIG. 1B. The lines on the disks mark the intersections of the surfaces of the disks and the surface of water, representing the angle formed by the surtax qfthedisks and the surface of water FIG. 2 is a schematic front view of the vessel equipped with a waterdrag- reducing structure in FIG. 1. The vessel is in motion.

FIG. 3 is a sectional view of the group of components comprising a disk (2) fastened to the hull (1) of the vessel through the central axle (3) and the holding frame (5); bearings (4) are fixed between the disk and the central axle.

FIG. 4 is a sectional view of the group of components comprising a disk (2) fastened to the hull (1) of the vessel through the central axle (3) and the holding frame (5); bearings (4) are fixed between the central axle and the holding frame.

FIG. 5 is a cross-sectional schematic presentation of a watercraft with a waterdrag-reducing structure; the watercraft is in motion on surface of water; a structure of disks at the stern monitors the upward and downward angles.

FIG. 6 is a schematic perspective presentation of the component monitoring the upward and lateral angles of the disks.

FIG. 7 is a top view through the body of the vessel of the waterdrag-reducing structure; the vessel is moving at low speed; the structure monitoring the changes between upward and lateral angles works by rotation like turning a compass.

FIG. 8 is a schematic cross-sectional presentation of a watercraft with a waterdrag-reducing structure as shown in FIG. 7.

FIG. 9 is a schematic front presentation of a watercraft with a waterdrag- reducing structure as shown in FIG. 7.

FIG. 10 is a top view through the body of the vessel of the waterdrag- reducing structure; the vessel is moving at high speed; the structure monitoring the changes between upward and lateral angles works by rotation like turning a compass.

FIG. 11 is a schematic cross-sectional presentation of a watercraft with a waterdrag-reducing structure as shown in FIG. 10.

FIG. 12 is a schematic front presentation of a watercraft with a waterdrag- reducing structure as shown in FIG. 10.

FIG. 13 is a top view through the body of the vessel of the waterdrag- reducing structure; here the waterdrag-reducing structure also function as a brake thanks to the structure monitoring the changes between upward and lateral angles like turning a compass.

FIG. 14 is a schematic cross-sectional presentation of a watercraft with a _ a. teag=x_educing structure as FIG. 15 is a schematic front presentation of a watercraft with a waterdrag- reducing structure as shown in FIG. 13.

FIG. 16 is a schematic cross-sectional presentation of a watercraft with a waterdrag-reducing structure with the ship in motion of the surface of water; the surface of the disk has an upward slant because the longitudinal axis of the disk forms an angle with the longitudinal axis of the propeller.

FIG. 16A is a schematic cross-sectional presentation of a watercraft with a waterdrag-reducing structure with the ship in motion of the surface of water; the surface of the disk has an upward slant because the weight of the vessel at the back is greater than at the front.

FIG. 17 is the cross-sectional drawing of a disk with waves working as rudders.

FIG. 18 is a plan view of a disk designed as in FIG. 17.

FIG. 19 is the cross-sectional drawing of a disk with vane blades to increase propulsion and lift.

FIG. 20 is a plan view of a disk designed as in FIG. 19.

FIG. 21 is a schematic front presentation of a watercraft with a waterdrag- reducing structure; the watercraft is in motion; the disks are designed as in FIG. 19 and FIG. 20.

FIG. 22 is a schematic front presentation of a watercraft with a waterdrag- reducing structure; the watercraft is in motion; the pairs of disks are arranged in V pattern.

FIG. 23 is a schematic front presentation of a watercraft with a waterdrag- reducing structure; the watercraft is in motion; the pairs of disks are arranged in V pattern; the propellers are in the middle of the V pattern.

FIG. 24 is a schematic sectional drawing of the waterdrag-reducing structure also functioning as a rudder as shown in FIG. 1.

FIG. 25 is a cross-sectional view of a disk shaped like a truncated cone.

FIG. 26 is a cross-section of a disk shaped like two reversed truncated cones piled one on top of the other.

FIG. 27 is a cross-section of a disk shaped like two reversed segments of a sphere piled one on top of the other; inside is a skeleton.

FIG. 28 is a cross-section of a disk shaped like a wheel; inside is a porous <BR> <BR> <BR> FIG. 29 is a cross-section of a disk with an rubber tire-like rim.

FIG. 30 is a schematic perspective presentation of a watercraft with a waterdrag-reducing structure; the watercraft is in motion on the surface of water; the disks are designed as in FIG. 29.

FIG. 31 is a schematic perspective presentation of a watercraft with a waterdrag-reducing structure; the watercraft is in motion on land; the disks are designed as in FIG. 29.

FIG. 32 is a schematic front view of a watercraft with a waterdrag-reducing structure; the watercraft is in motion on the surface of water; the twin-hull is shaped like a reverse V.

FIG. 33 is a plan view of an endless chain with flat panels fixed to the links of the chain.

FIG. 34 is a plan view of an endless chain designed as in FIG. 33 and fixed to the hull of the watercraft.

FIG. 35 is a schematic cross-section of a waterdrag-reducing structure where the disks are substituted by an endless chain designed as in FIG. 33.

FIG. 36 is a schematic front presentation of a watercraft with a waterdrag- reducing structure with the vessel in motion of the surface of water; the waterdrag- reducing structure is designed as an endless chain, as in FIG. 35.

FIG. 37 is a plan view of an endless belt with flat panels on the rim of the belt.

FIG. 38 is a sectional drawing of the endless belt as designed in FIG. 37 and fixed to the hull of the watercraft.

FIG. 39 is a side view of a watercraft with a waterdrag-reducing structure, where the waterdrag-reducing system is an endless belt; the endless belt is wide; the transversal axis of the belt and the transversal axis of the vessel are parallel; the vessel and the waterdrag-reducing structure are in motion on the surface of water.

FIG. 40 is a schematic front view of a watercraft with watercraft-reducing structure as designed in FIG. 39. ;.....

FIG. 41 is a side view of a watercraft with a waterdrag-reducing structure in motion on the surface of water; the waterdrag-reducing structure is an endless belt; hollow cylindrical volumes are fixed on the surface of the endless belt; these follow volumes are parallel to one another and parallel to the transversal axis of the belt.

FIG. 42 is a front presentation of a watercraft with a waterdrag-reducing struAre asZdesigned in FIG. 4 1 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS - As illustrated in FIG. 1, FIG. 1A, FIG. 1B, FIG. 1C, FIG. 1D, FIG. 2, FIG.

3, FIG. 4, the waterdrag-reducing structure for watercraft in this preferred embodiment comprises the following: at least two rows of flat disks, each flat disk 2 fixed to its central axle 3; the central axles 3 of the disks are fixed to the hull 1 of the watercraft, or the central axles 3 of the disks are fixed to shafts 5 then these shafts 5 are fixed to the hull 1 of the watercraft, forming symmetric rows of disks running lengthwise under the hull of the watercraft ; these disks 2 can revolve endlessly thanks to bearings 4 set in the middle of the disks between the disk and the central axle or between the central axle and the hull of the vessel, or between the central axle and the shaft holding the central axle; when fixing the disks 2 to the hull 1 of the watercraft, the surface of the disk must form an upward angle alpha with the longitudinal axis la of the hull of the watercraft, and this alpha angle should be < 30 degrees; at the same time, the surface of the disk 2b must form a lateral angle beta with the transversal axis lb of the body of the disk, and this beta alpha should be < 30 degrees ; thanks to the symmetric distribution of the disks on the two sides under the hull of the watercraft, the weight of the vessel is evenly distributed to all the disks 2; when the watercraft is moving thanks to the thrust from the propeller 7, the alpha angle and beta angle remain almost the same as the alpha and beta angles when the vessel does not move ; thanks to the upward alpha angle of the surface of the watercraft 2 with the longitudinal axis 1 of the watercraft, the disk 2 is lifted up when the watercraft moves forward thanks to the thrust from the propeller 7; thanks to the lateral angle beta of the surface of the disk with the hull of the watercraft, only the lower part of the surface of the disk remains under water when the watercraft'moves ahead ; and since the underwater part of the surface of the disk, can revolve endlessly with an axis parallel to the axis of motion of the watercraft and in the opposite direction of motion of the watercraft, the comparative velocity between the surface of the disk and the surrounding water is small; since the contact of the lower part of the surface of the disk and the surrounding water takes place under water, the watercraft stands less action from the waves on the surface <BR> <BR> <BR> of water.....,. 0).

- As illustrated in FIG. 5, the waterdrag-reducing structure in this preferred embodiment comprises: at least one pair in the row of pairs of disks symmetrically arranged under the hull of the vessel is equipped with an apparatus monitoring the alpha and beta angles; since these alpha and beta angles can be made wider or narrower, the lift force on the disks can be made stronger or less and the watercraft can be made to move with greater or smaller speed while the hull of the watercraft keeps on staying above water; since the lateral angle can be modified, the contact surface of the lower part of the disks with water can be increased or reduced.

- As illustrated in FIG. 5 and FIG. 6, the waterdrag-reducing structure for watercraft in this preferred embodiment has an apparatus for monitoring the upward angle alpha or the lateral angle beta; this apparatus comprises: a hinge 8 set between the central axle of the disk 3 and the shaft 5 holding the central axle of the disk; at least two control levers fixed to the central axle 3 of the disk: lever 9a on the longitudinal axis of the disk and lever 9b on the transversal axis of the disk; pulling or pushing these levers will create the pulling or pushing force to modify the upward angle alpha or lateral angle beta of the surfaces of the disks.

- As illustrated in FIG. 7, FIG. 8, FIG. 9, the waterdrag-reducing structure for watercraft in this preferred embodiment has flat disks with adjustable upward angles alpha and lateral angles beta. The structure comprises: the flat disks 2 are fixed to their central axles 3 which are fixed to the shafts 5 holding the central axles ; the shafts 5 are joined to the pivots 10 which joined the structure to the vessel and can monitor the rotation; the pivots 10 are vertically fastened to the hull (that is, at a right angle with the floor plane of the vessel); the central axles 3 of the disks and the pivots monitoring the rotation will form a fixed angle gamma, resulting in a conjugate angle since the surface of the disk and the surface of water also form an angle equal to this gamma. angle ; this fixed gamma angle should be < 30 degrees. when the watercraft starts moving as illustrated in FIG. 7, FIG. 8 and FIG. 9, the vertical pivot 10 will rotate so that the disks 2 will be in such a position that the upward angle alpha is larger, resulting in a greater lifting force needed when the - initial-speed-of the. watercraft is still lo> ;, __ _ _- when the watercraft is moving faster and faster, as illustrated in FIG. 10, FIG. 11 and FIG. 12, the vertical pivot 10 will rotate the central axle 3 in an arc; the upward angle alpha will decrease and the lateral angle beta will increase; the angle changes will facilitate the increase in speed of the watercraft since the direction of the surface of the lower parts of the disks is getting more parallel to the direction of motion of the watercraft, the disks 2 rotate more easily and so the waterdrag is getting smaller; however, the disks will not be in a position completely without an alpha angle, for in such a position the disks will not create a lifting force.

- As illustrated in FIG. 13, FIG. 14 and FIG. 15, the waterdrag-reducing structure in this preferred embodiment comprises flat disks with an apparatus for adjusting upward angles alpha and lateral angles beta, thus giving the structure an extra function of a brake; this apparatus comprises: the vertical pivots 10 turn the central axles 3 of the disks in an arc and brings the disks to the position as illustrated in FIG. 13, FIG. 14, FIG. 15, wherein the surfaces of the disks 2 make a downward angle with the longitudinal axis of the watercraft; consequently, the lower parts of the disks have a downward slant, coming nearer to a right angle with the direction of motion of the watercraft, producing more resistance to water leading to slowering the moving watercraft.

- As illustrated in FIG. 16, the waterdrag-reducing structure for watercraft in this preferred embodiment comprises: at least two flat disks 2 or two rows of flat disks, each disk fixed to a central axle 3; the central axles 3 of the disks are fixed to the hull 1 of the watercraft ; the surfaces of the disks must make an upward angle about the same width as the alpha angle with the horizontal axis of the propeller ; the transversal axis of the disk and the transversal axis of the watercraft make a beta angle; since the surfaces of the disks 2 make an upward angle about the same width with the alpha angle with the longitudinal axis of the propeller 7, the propulsion from the propeller will exert a lifting force on the disks; since the surfaces of the disks 2 make also a lateral angle beta with the transversal axis 2b of the watercraft (or with the surface of water), only the lower part of the disks will remain in water; since this lower part of the disks can revolve endlessly with an axis nearly parallel to the axis of motion of the watercraft and in the opposite direction of the direction of. otion of the watercraft, the comparative velocity between the lower surfaces of the disks and the surrounding body of water is small; and since the contact between the lower part of the disks and the surrounding water takes place under water, the watercraft bears less action from the surface waves.

- As illustrated in FIG. 16A, the waterdrag-reducing structure in this preferred embodiment for watercraft comprises : at least two disks 2 or two rows of disks fixed to the hull of the watercraft and symmetrically arranged on two sides of the longitudinal axis of the watercraft ; each disk is fixed to its central axle 3; this central axle is fixed to the hull 1 of the watercraft; these disks will be fixed to the hull so that the surfaces of the disks are parallel to or make an narrow upward angle with the longitudinal axis of the watercraft; at the same time, the surfaces of the disks will also form a lateral angle beta with the transversal axis lb of the watercraft ; the weight of the watercraft will be arranged in such a way that the stern will be heavier than the bow, thus, the longitudinal axis la of the vessel will make an upward slant with the surface of water (about the same width as the alpha angle), with the result that the surfaces of the disks also make an upward angle alpha with the surface of water; that is why, when the propeller 7 works and pushes the watercraft forward, the disks are lifted up; the surfaces of the disks form a lateral angle beta with the transversal axis of the watercraft (and also with the surface of water); the lower portions of the disks which remain under water can move with an axis parallel to the axis of movement of the watercraft in the opposite direction of the direction of movement of the watercraft ; that is why, the comparative velocity between the underwater portions of the disks and the body of water surrounding them is small and the friction caused by water is greatly reduced; and as the lower parts of the disks in contact with water remain under water, the watercraft does not suffer to much action from waves at the surface of water.....

- The waterdrag-reducing structure for watercraft in this preferred embodiment is given a further function of a brake for the watercraft (no illustration); this structure comprises at least a pair of symmetric disks which can be monitored to reduce or stop the rotation; this velocity monitoring leads to the reduction or increase of the friction between the surfaces of the disks and the suffounding body of water; this frictiqn helps reduce jiie speed oftheyesseL - The waterdrag-reducing structure for watercraft in this preferred embodiment is given a further function of a rudder for the watercraft (no illustration); at least one disk of every pair of symmetric disks will be imparted the capability to reduce or stop or increase the speed of rotation of the disk; this speed monitoring on one side of the watercraft leads to the difference of water friction between the two rows of disks, resulting in the change of direction of the watercraft.

- The waterdrag-reducing structure for watercraft in this preferred embodiment can also increase the thrust and lift forces of the watercraft ; at least one pair of disks in every row of symmetric disks can be forced to rotate by driving force from a motor; the velocity of the sides of the disks should be greater than the velocity of the hull of the watercraft compared to the surface of water; since the lower portions of the surfaces of these disks which are forced to rotate by driving force remain under water and move in the opposite direction to the direction of movement of the watercraft, they create a current moving downward and backward, resulting in more thrust and lift for the watercraft.

- As illustrated in FIG. 17, FIG. 18, FIG. 19, FIG. 20, FIG. 21, the waterdrag- reducing structure for watercraft in this preferred embodiment has disks on whose surfaces are fixed protuberances shaped like waves 11, paddles 12, holes 13 or wind vanes 14; when the disks rotate by the driving force from the motor, these protuberances will create a stronger current moving backward and downward which increase the thrust and lift on the watercraft; as a result, the watercraft will be able to move at different speeds while remaining constantly above water.

- As illustrated in FIG. 1, FIG. 1A, FIG. 1B, FIG. 1C, the waterdrag-reducing structure for watercraft in this preferred embodiment comprises rows of flat disks overlapping one another like fish scales or like floor tiles; thanks to these arrangements, the comparative movement between the underwater surfaces of the disks and the surrounding water is straighter, the currents are less deviated by the rotation of the disks, the consumption of energy is reduced and the whole structure is less bulky.

- As illustrated in FIG. 26, the waterdrag-reducing for watercraft in this preferred embodiment comprises two pairs of disks or two pairs of rows of disks symmetrically arranged on both sides of the longitudinal axis of the watercraft, one ,--pair-of-disks-or-. rows of disks fixed under the front part of the hull of the watercraft and the other pair fixed under the rear part of the hull of the watercraft ; the disks fixed under the rear part of the watercraft have an upward angle alpha which can be adjusted and changed to a downward angle; since the alpha angle of the pair of disks or rows of disks at the rear part of the watercraft can be changed to a downward angle, the motion ahead of the watercraft will give the longitudinal axis of the watercraft an upward angle with the surface of water; as a result, the alpha angle of the surfaces of the disks at the front part of the watercraft will also change; that is why, the vessel will be able to move at different speeds while the hull is always out of water.

- As illustrated in FIG. 21, FIG. 22, FIG. 23, the waterdrag-reducing structure for watercraft in this preferred embodiment comprises at least one pair of disks or one pair of rows of disks fixed under the hull in a V pattern: the surfaces of the disks of the two sides have reverse beta angles and the lower parts of the disks point to the middle; since the lower parts of the symmetrical disks point to each other, the current formed will move between them; as the centrifugal motion caused by the rotation of the disks is reduced and the water moves directly to the stem, the consumption of energy is decreased.

- As illustrated in FIG. 23, the waterdrag-reducing structure for watercraft in this preferred embodiment comprises a propeller 7 positioned between the pairs of disks or rows of disks arranged in V-pattern ; when the propeller 7 works and moves the vessel ahead, the rotation of the propeller creates a current of water and pushes this current backward; this current of which a great part is deviated by the centrifugal force will be directed straighter between the lower parts of the disks and exert more thrust on the vessel.

- As illustrated in FIG. 1, FIG. 2, FIG. 24, the waterdrag-reducing structure for watercraft in this preferred embodiment will be equipped with an apparatus working like a rudder to monitor the steering of the watercraft ; this apparatus comprises at least one vertical flat disk 2r; its central axle 3r is fixed to a shaft Sr and a pivot lOr which is vertically fixed to the rear part of the hull of the watercraft ; when the watercraft is moving ahead in a straight line, the surface 2r of the disk is parallel to the longitudinal axis of the vessel with the lower part of theFdisk_ in water; since only the lower part of the disk 2r is under water and can rotate, it will not cause water drag when the vessel is moving; rotating the pivot lOr will change the orientation of the surface of the disk and deviate the current of water to the rear of the vessel with an axis and direction opposite to the axis and direction of motion of the watercraft ; consequently, the watercraft will be able to change the direction of its course without causing much friction, as the comparative velocity between the contact surface of the disk and the surrounding water is small. water is small.

- As illustrated in FIG. 25, FIG. 26, FIG. 27, FIG. 28, FIG. 29, the waterdrag- reducing structure for watercraft in this preferred embodiment comprises: flat disks either hollow or. porous with thick walls reinforced by a skeleton; these disks will be shaped like cylinders or truncated cones or two reversed cones one on top of the other or two reversed segments of sphere one on top of the other; the thick walls and the hollow/porous design increase the sturdiness and buoyancy of the structure.

- As illustrated in FIG. 30, the waterdrag-reducing for watercraft in this preferred embodiment comprises disks made of resilient substances filled with air and mounted on rims like wheels; as a result, the disks will improve buoyancy and work as shock absorbers for the watercraft.

- As illustrated in FIG. 30, FIG. 31, the waterdrag-reducing structure for watercraft in this preferred embodiment will give the watercraft the capability to travel on land. The structure comprises disks 2 made of resilient materials working as wheels; there is a join 3kt between the central axle 3e of the disk and the shaft 5 fixing it to the hull; this joint allows the central axle of the disk to change between two positions: parallel to the transversal axis of the watercraft or vertical to the longitudinal axis of the watercraft, thus allowing the disks to work as wheels for the watercraft, when moving on land.

- As illustrated in FIG. 32, the waterdrag-reducing structure for watercraft in this preferred embodiment is designed for watercraft cavities under the hull; these cavities are V-shaped or W-shaped on a cross-section of the watercraft ; the rows of disks are arranged along the walls under the hull of the watercraft ; as the disks are arranged close to the walls under the hull of the watercraft, w th3 distance separati1lg the disks frB the hull of the vessel is closer, thus, giving better balance to the vessel when it is moving.

- As illustrated in FIG. 33, FIG. 34, FIG. 35, FIG. 36, the waterdrag-reducing structure for watercraft in this preferred embodiment adopts another solution wherein the endless disks are substituted by endless chains. These endless chains consist of : at least one closed chain 15 stretched at both ends by two gear wheels 16 with their axles 17 fixed to a frame 18, panels 2p are fixed to the bushings 19 of rings 20 of the chain; the panels have their free ends pointing out of the area of the chain and the surfaces of the panels are parallel to the surface made by the circumference of the chain; this chain 15 is fixed to the hull 1 of the vessel through the axles 5p of the gear wheels; just as in the solution using disks, the chain will be fixed to the hull so that the surface of the chain 15, which is also the surface of the panels 2p, forms an upward slant with the longitudinal axis la of the watercraft and a lateral slant beta with the transversal axis lb of the watercraft ; since the surfaces of the panels 2p on the chain 15 forms an upward slant alpha with the longitudinal la of the watercraft 1, when the watercraft moves thanks to the thrust from the propeller 7, the panels are lifted up; and since the surfaces of the panels forms an lateral slant beta with the transversal axis 1b of the hull of the watercraft, only the surfaces of the panels 2p on the lower portion of the chain 15 stay under water when the watercraft moves ; and since these panels 2p on the lower face of the chain 15 remain under water and can move with axis of motion parallel to the axis of motion of the watercraft and in the opposite direction of the movement of the watercraft, the comparative velocity between the surfaces of the panels 2p on the lower portion-of the chain 15 under water and the surrounding body of water is small, resulting in noticeable reduction of water drag; and since the surfaces of the panels on the lower part of the chain in contact with water are under water, the watercraft which travel above the surface of water does not bear much action from the waves.

- As illustrated in FIG. 37, FIG. 38, the waterdrag-reducing structure for watercraft in this preferred embodiment adopts a similar solution to the above solution, wherein the endless disks are substituted by endless belts. These endless bOAs-consist of flat panels 2p,. on whose surfaces 2q are fixed the axles 3q with bearings 4q, two boards shaped like rectangles with two circular ends 5q, on whose rims or near the rims of one of their faces are grooves 6q running all round their perimeter; these two panels 5q are parallelly placed with the grooved surfaces facing each other; the flat panels 2q are placed between the two boards 5q so that their axles 3q with bearings 4q running in the grooves 15 of the boards; the flat panels 2q are fastened together by such means as springs 16 through their axles 3q ; thus, these flat panels 2q fastened together form an endless belt with the flat panels. 2q pointing out of the circumference of the two boards 5q ; the surfaces of the flat panels 2q are parallel to the surfaces of the two boards 5q ; in this way, the flat panels 2q are joined together and form. an endless belt with bearings 4q running on the rim of the circumference of the two boards 5q ; on the surfaces of the boards are the shafts 51 joining the boards to the hull 1 of the watercraft ; and like the solution with an endless chain, the endless belt will be fixed to the watercraft in the same way and will fulfill the same function as the endless chain as mentioned in the above solution.

- As illustrated in FIG. 39, FIG. 40, the waterdrag-reducing structure in this preferred embodiment adopts another solution wherein: at least a closed tubular belt 17 made of soft or elastic material and shaped like an automobile inner tube, this belt 17 is stretched out by at least two large pulleys 18 with central axles fixed to a frame 19; the grooves 20 of the pulleys 18 are the same with as the diameter of the belt; the belt 17 runs continuously on the pulleys 18 and forms an endless belt; this endless belt 17 is fastened to the hull 1 of the watercraft through the axles 21 of the pulleys; the axles 21 of the pulleys are fixed to the frame 19 holding the axles of the pulleys; this frame 19 is fixed to the hull 1 ofthewatercraAandto the horizontal shaft 17a of the endless belt; the horizontal shaft 17a of the belt and the horizontal axis 7a of the propeller 7 make an upward angle; the vertical axis 17b of the belt 17 makes a right angle with the horizontal axis lb of the watercraft ; the hollow or porous character of the structure and the large size of the belt 17-increase the buoyancy of the wat, rcraft, ;. on account of the upward anglet. of the lower surface of the belt with the horizontal axis 7a of the propeller 7, when this propeller operates, the lower surface of the lower part of the belt enters in contact with water and moves in the opposite direction of the direction of motion of the watercraft, deviating the current of water downward and backward and consequently lifts up the watercraft ; when the vessel moves forward with enough speed, only the lower face of the endless belt and moves in the opposite direction of the direction of the vessel, leading to the reduction of waterdrag.

- In the above-mentioned solution, it is better if the waterdrag-reducing structure for watercraft (no illustration) consists of : at least two endless belts 17, one fixed under the front part of the hull of the watercraft, the. other fixed under the back part of the hull of the watercraft ; the endless belts are fixed, to the hull of the watercraft through the axles of the pulleys or through the frame holding these axles; the surface of the belt makes an upward angle with the longitudinal axis of the watercraft; the surface created by the perimeter of the belt is parallel to the vertical surface containing the longitudinal axis of the belt; thanks to the hollow or porous nature of the belt and the large size of the belt, the buoyancy of the watercraft increases ; the upward angle of the lower surface of the belt with the longitudinal axis of the watercraft remains constant because the weight of the watercraft is evenly distributed to these belts; therefore, when the watercraft moves ahead, the lower part of the belt enters in contact with water and moves in the opposite direction of the direction of motion of the watercraft, deviating the current of water downward and backward and consequently the watercraft is lifted up; when the vessel moves forward with enough speed, only the lower face of the large belt moves in the opposite direction of the direction of the. vessel, leading to the reduction of waterdrag.

- As illustrated in FIG. 41, FIG. 42, the waterdrag-reducing structure in this preferred embodiment adopts another solution wherein : at least one endless belt 17g or chain (not presented on drawings because of similarity with belt); this belt is stretched out by at least two large pulleys 18g with- central axles fixed to a frame 19g, or the chain is stretched out by at least two chain gears with central axles fixed to a frame 19g ; on the outer surface of the belt 17g or chain are fixed hollow volumes 21 or floats shaped like rectangular columns; these hollow volumes are parallel to one another and perpendicular to the longitudinal axis 17ga of the endless belt or chain; this endless belt 17g or chain is fastened to the hull 1 of the watercraft through the frame 19g holding the pulleys or gears; the lower surface of the belt makes an upward angle with the horizontal axis 7a of the propeller 7 of the watercraft; the surface created by the perimeter of the belt 17g is parallel to the vertical surface containing the longitudinal axis of the hull 1 of the watercraft; the hollow or porous character of the volumes or floats 21 and their large volume increase the buoyancy of the watercraft; on account of the upward angle of the lower surface of the belt or chain with the horizontal axis 7a of the propeller 7, when this propeller enters in operation, the volumes or floats 21 on the lower part of the belt or chain enter in contact with water and move in the opposite direction of the direction of motion of the watercraft, deviating the current of water downward and backward and consequently the watercraft is lifted up; when the vessel moves forward with enough speed, these volumes or floats. are in contact with water and move in the opposite direction of the direction of the vessel, leading to the reduction of waterdrag.

- Just like in the above-mentioned solution, the waterdrag-reducing structure in this preferred embodiment (no illustration) should comprise: at least two endless belts or chains, one belt or chain fixed under the front part of the hull of the watercraft, the other fixed to the back part of the hull of the watercraft; these belts or chains are fixed to the hull of the watercraft through the axles of the pulleys or through the frame holding these pulleys; the lower surfaces of the belts form an upward angle with the longitudinal axis of the hull of the watercraft; the vertical axis of the belts makes a right angle with the horizontal axis of the hull; the hollow or porous nature of the volumes or floats fastened to the belt and the dimension of the belts increase the buoyancy of the watercraft; on account of the upward angle of the lower surface of the belt or chain with the longitudinal axis of the watercraft remained constant because the weight of the watercraft is evenly distributed among the belts or chains, therefore when the watercraft moves ahead, the lower part of the belt or chain enters in contact with water and moves in the opposite direction of the direction of motion of the watercraft, deviating the current <BR> <BR> <BR> of water downward and backward and consequently the watercraft is lifted up ;<BR> <BR> when the vessel moves forward with enough speed, thanks to the large surface of the belt, only the lower portion of the belt moves in the opposite direction of the direction of the vessel, leading to the reduction of waterdrag.

Although the specific characteristics of the present invention have been described in detail in the above preferred embodiments with their illustrations, it should be understood that there are other ways to implement the previously explained principles of the present invention, among them are possible modifications, improvements, substitutions of the structure or of the details, all within the limits of the expressed principles of this invention and also within the ground covered by this invention and clearly defined in the claims that follow.